Irregularly oblate 0.5~1.5 cm in diameter. Externally yellow or yellowish-brown, irregularly reticulate-wrinkled. Apex with slight dented stem scars, base usually tuberculate. Texture hard and fragile, fracture yellow, horny, waxy-shinny. Odour, slight; taste, bitter.

Chest pain, epigastric pain; amenorrhea, dysmenorrheal, blood stasis after childbirth; traumatic swelling and pain.

Having the efficacies of promoting blood circulation to remove blood stasis and promoting circulation of qi to relieve pain, the drug is prescribed for alleviation of pain in the gastric cavity, abdomen and hypochondrium due to stagnation of blood and qi, dysmenorrhea due to blood stasis, mass in the abdomen, and abdominal pain due to blood stasis after delivery. It can also be used for hernial pain, general pain (pain all over) due to stagnation of blood and qi, and traumatic injury.

Corydalis tuber is specialized in promoting circulation of blood. The raw drug is mainly used for chest pain caused by stagnation of the heart blood, amenorrhea due to blood stasis, pain and tenderness in the lower abdomen, etc. Vinegared corydalis tuber is liable to release its active principles when decocted and is able to guide the drug into the liver, strengthening its effectiveness in alleviating pain. So it is often used for hypochondriac pain due to stagnation of the liver-qi, stomachache due to stagnation of the stomach-qi, hernial pain, etc.